Checking device for single and double cable cableways with automatic clamping

ABSTRACT

In cableways in which each car is frequently coupled and decoupled from the traction cable by means of an automatic locking clamp arranged on the principal trolley, a device, independent of the coupling device arranged on the car trolley, for checking the grip of the car coupling clamp on the traction cable.

United States Patent Inventor Maurizio Primo Milan, Italy Appl. No. 864,820 Filed Oct. 8, I969 Patented June 22, I971 Assignee Cerettl & 'Ianllni Milan, Italy Priority Feb. 3, I969 Italy l2374A/69 CHECKING DEVICE FOR SINGLE AND DOUBLE CABLE CABLEWAYS WITH AUTOMATIC CLAMPING 4 Claims, 5 Drawing Figs.

US. Cl 104/173, 104/202, 73/133 Int. Cl B6lb 11/02,

[50] Field oi Search 104/165, 173, 202, 204

[56] References Cited UNITED STATES PATENTS 2,769,400 1 1/ I956 Wallmannsberger......... 104/202 3,394,661 7/1968 Muller I04/202 3,405,652 10/1968 Mez l04/204 Primary Examiner-Arthur L. La Point Assistant Examiner-Robert Saifer Anomey-Gausewitz and Carr ABSTRACT: In cableways in which each car is frequently coupled and decoupled from the traction cable by means of an automatic locking clamp arranged on the principal trolley, a device, independent of the coupling device arranged on the car trolley, for checking the grip of the car coupling clamp on the traction cable.

PATENTEUJUNZZIBYI 3,585,941

SHEET 2 OF 3 INVENTOR MAUF/Z/O r g/M0 ATTORNEYfl CHECKING DEVICE FOR SINGLE AND DOUBLE CABLE CABLEWAYS WITH AUTOMATIC CLAMPING In cableways in which each car is frequently coupled and decoupled from the traction cable by means of an automatic locking clamp arranged on the principal trolley (which in the following will be indicated by the name of clamped trolley for brevity), it is necessary after each coupling to check if the grip of the clamp is entirely efficient and such as to guarantee the required safety during the outward or return journey of the car.

Conventional checking devices for this purpose have not given satisfactory results insofar as they are not capable of guaranteeing with certainty the safe locking of the clamp on the cable, either because of errors due to the components used or because of the shortness of checking time.

The object of this invention is a checking device which satisfies the most severe working requirements and which, being independent of the coupling device arranged on the car trolley, can also be applied to existing installations.

The device comprises a checking carriage which moves on wheels along a path of its own which is rigid with the guardrail of the path of the clamp trolley; a motor which causes said carriage to advance autonomously with a velocity slightly less than that of the clamp trolley in order to permit this latter to reach the carriage without appreciable impact and drag it beyond; a braking means acting with a preestablished torque value on the carriage; and finally a tracer carried by the carriage and maintained in contact with the traction cable which senses possible relative sliding between the cable and clamp trolley in the case of defective grip of the clamp, and in such a case to operate a signal device and switch for stopping the operation; the rail for the carriage being provided with a terminal ascending ramp for causing detachment of the carriage from the clamp trolley after checking and the cessation of braking torque in order to allow the carriage to return by inertia to its initial position.

The carriage is coupled to a cable loop which runs between two pulleys located at the ends of the path of travel of the carriage, one of said pulleys being driven by a reversible electric motor in order to furnish the motor torque necessary for the advancement of the carriage up the point where this latter is reached by the clamp trolley, and then to furnish by reverse motion the brake torque during dragging of the carriage by the clamp trolley. The said motor is controlled by remote switches actuated by suitable contacts arranged along the path of travel, a first contact being actuated by the clamp trolley in order to start the motor and make the carriage advance, a second contact being actuated by the carriage successive to the moment of impact between the clamp trolley and carriage, and a third contact being actuated at the end of travel of the carriage as it abandons the trolley, in order to cut off the current and allow the carriage to return to its initial position.

One embodiment of the invention is illustrated in the attached drawing in which:

FIG. 1 is a diagrammatic view of the device applied to a cableway;

FIG. 2 is a diagrammatic view of the carriage which is dragged by the clamp trolley;

FIG. 3 is a sectional view through the line Ill-Ill of FIG. 2;

FIG. 4 is a side view of the carriage;

FIG. 5 is a plan view of the carriage.

With reference to the drawings a clamp trolley I supports a cable car by means of an arm 101 and slides along the path of travel, constituted by a pair of lower rails 103 and a pair of upper guardrails 104 by way of wheels 102. Said trolley is provided with automatic mechanisms for locking its clamp in order to render the trolley (and hence the car) rigid with the traction cable 2. Said mechanisms which are well known in themselves are not shown and do not form part of the invention. The path of travel of a carriage K is indicated with the reference numeral 4, said path 4 consisting of two opposing U- rails fixed to the guardrail 104 and having a length of about 4 meters and terminating in an ascending ramp 5.

The carriage K is anchored by its end pivots 16 and 17 to the ends of a cable 6 which forming a closed loop runs between two pulleys 7 and 8, pulley 3being the driving pulley and pulley 8 the driven pulley, this latter provided with an expander 9 acting on the support 10. The pulley 7 is keyed to the exit shaft ll' of a fixed motor with reduction gear II the motor of which is fed with 3-Phase current from the principal supply, said motor being connected to said supply by way of a reversing switch which allows two phases of feed current to be reversed with consequent reversion of the direction of rotation.

The carriage consists of two frames, an inner frame 12 and outer frame 13, the former sliding with respect to the latter, these frames linked together by way of two lateral thrust springs 14-15 acting between the heads 114 and of the pivot 116 of the internal trolley 12 and between the heads 117 and 118 of the pivot 119 of the external frame 13. Said springs are contained in sheaths -121. The outer frame 13 is provided with two pivots 16-17 which, in addition to serving as anchorage for the ends of the looped cable 6 support the two pairs of wheels 18-19 which rest on the path of travel 4.

The internal frame 12 is provided with vertical appendices 40-40 which support pivots on which two coaxial rollers of elastic material 41 are mounted against which the clamp trolley I rests when it reaches the carriage K (FIG. 2). The internal frame is also provided with a pivot 20 which moves vertically against a return spring 21, said pivot supporting at its lower end a control roller 22 and at its upper end a pivot 23 on which is pivoted the end of a lever 24 pinned to the frame at 25. At the end of said lever 24 an arm 27 is pivoted at 26 which supports a tracer 28 of arched shape mounted at its lower end, this tracer having a rubber base 29 for contact with the cable 2 and is rigidly secured to the pivot 30 which moves axially in the seat formed in the arm 27 against a return spring 31. The upper end of the arm 27 is connected at 32 to one end of the compression spring 33 which is secured at its other end to the pivot 34 fixed to the lever 24.

The arm 27 is maintained by the thrust of spring 33 against the fixed stop pivot 151 which has an elastic sheath 152. Should the head of the arm 27 move angularly towards the left of the Figure, it actuates the pushbutton 35 of a signalling 36 and control device for stopping the operation of the cableway, by way of a plate 34. An elastic stop 37 dampens the impact of the carriage against a limit buffer 42 when it returns to its initial position after the checking operation has been carried out. A device 38 supported on the frame 13 is furnished with a switch and pilot light which is extinguished by the action of the plate 43 when the minimum test force has been obtained. A stop of elastic material 12' dampens the impact between the internal frame 12 and the cross piece 13 of the outer frame 13.

The device operates in the following manner:

After the clamp trolley 1 has been automatically coupled to the traction cable 2, said trolley actuates during its path of travel a first contact Fcl which starts the motor 11 and consequently causes the carriage K to move. Said contact is arranged in such a position that the clamp trolley can reach the carriage after the latter has traveled about 1 meter, at this point the difference in velocity between these two components being very small. A second contact F02 is actuated immediately after the coupling together of the carriage and trolley and causes inversion of two feed current phases of the motor 11. In this way the force exerted by the cable 6 in the opposite direction to the preceding is transmitted by the outer frame 13 to the inner frame 12 of the carriage, so providing the brake torque for checking, which remains constant over the whole of the length of the test section, equal to about 2 meters.

At the end of this section the carriage K rises up the ascending ramp 5 and on abandoning the clamp trolley actuates a third contact Fe 3 which, by operating a time switch, cuts off the current to the motor 11 with a small safety time lag, so that the carriage K can return by the action of its own inertia to its initial position with reduced speed. When the clamp trolley reaches the carriage K it touches the elastic rollers 41, and

acts at the same time on the roller 22 and raises the pivot so causing lowering of the tracer 28 on to the traction cable. If the locking force of the clamp is greater than the said braking force there will be no sliding between the tracer and cable. if on the other hand the grip is not efficient there will be a sliding action between the trolley and the cable, because of which the tracer 30 will incline in the direction of the arrow 160 and the end of the arm 27 will release the pushbutton 35 of the signalling and control device 36, so causing stopping of the cableway.

For reasons of greater reliability and for the case in which the cableway because of unforeseen faults has to operate with its standby heat engine, provision is made for providing the braking test torque by means of a shoe brake and spring acting on the shaft of the motor lll, by way of a toothed coupling which in this case would be closed but which would normally be maintained open.

What we claim is:

l. A device for checking the grip of the car coupling clamp of the traction cable in single and double cableways with automatic clamping which comprises: a checking carriage which moves on wheels along a path of its own which is rigid with a guardrail of the path of the clamp trolley; a motor which causes said carriage to advance autonomously with a velocity slightly less than that of the clamp trolley in order to permit the latter to reach the carriage without appreciable impact and to drag it beyond; a braking means acting with a preestablished torque value on the carriage; and finally a tracer carried by the carriage and maintained in contact with the traction cable which senses possible relative sliding between the cable and clamp trolley in the case of defective grip of the clamp, and in such a case to operate a signal device and switch for stopping the operation of the cableway; the rail for the carriage being provided with a terminal ascending ramp for causing detachment of the carriage from the clamp trolley after checking and the cessation of braking torque in order to allow the carriage to return by inertia to its initial position.

2. A device as claimed in claim 1, in which the test carriage is inserted between the ends of a cable looped around two pulleys situated at the ends of the path of travel of the carriage; one of the said pulleys being driven by a reversible electric motor, in order that it can provide both the torque for driving the carriage and, on reversing, the braking torque acting on the carriage.

3. A device as claimed in claim 1, in which said electric motor is operated by way of remote switches arranged along the path of travel, a first contact being actuated by the clamp trolley for starting the motor for driving the carriage; a second contact being actuated by the carriage successive to the moment of impact between the clamp trolley and carriage; and a third contact being actuated at the end of the test path of the carriage, when this latter disengages itself from the clamp trolley, in order to remove current from the motor and allow the free return of the carriage to its final position.

4. A device as claimed in claim 1, in which the carriage comprises two frames one inner and one outer, the former sliding with respect to the latter, connected by means of springs which thrust in the longitudinal sense, the outer frame being anchored at its two ends to the ends of the cable loop, the inner frame being provided with two elastic rollers against which the clamp trolley rests and thrusts, and being further provided with a tracer member operated by a lever mechanism actuated by the clamp trolley for lowering on the traction cable; said tracer being interlocked with a device for signalling and interrupting the flow of electric current to the installation, and acting only in the case in which sliding occurs between the clamp trolley and traction cable under the action of the braking torque. 

1. A device for checking the grip of the car coupling clamp of the traction cable in single and double cableways with automatic clamping which comprises: a checking carriage which moves on wheels along a path of its own which is rigid with a guardrail of the path of the clamp trolley; a motor which causes said carriage to advance autonomously with a velocity slightly less than that of the clamp trolley in order to permit the latter to reach the carriage without appreciable impact and to drag it beyond; a braking means acting with a preestablished torque value on the carriage; and finally a tracer carried by the carriage and maintained in contact with the traction cable which senses possible relative sliding between the cable and clamp trolley in the case of defective grip of the clamp, and in such a case to operate a signal device and switch for stopping the operation of the cableway; the rail for the carriage being provided with a terminal ascending ramp for causing detachment of the carriage from the clamp trolley after checking and the cessation of braking torque in order to allow the carriage to return by inertia to its initial position.
 2. A device as claimed in claim 1, in which the test carriage is inserted between the ends of a cable looped around two pulleys situated at the ends of the path of travel of the carriage; one of the said pulleys being driven by a reversible electric motor, in order that it can provide both the torque for driving the carriage and, on reversing, the braking torque acting on the carriage.
 3. A device as claimed in claim 1, in which said electric motor is operated by way of remote switches arranged along the path of travel, a first contact being actuated by the clamp trolley for starting the motor for driving the carriage; a second contact being actuated by the carriage successive to the moment of impact between the clamp trolley and carriage; and a third contact being actuated at the end of the test path of the carriage, when this latter disengages itself from the clamp trolley, in order to remove current from the motor and allow the free return of the carriage to its final position.
 4. A device as claimed in claim 1, in which the carriage comprises two frames one inner and one outer, the former sliding with respect to the latter, connected by means of springs which thrust in the longitudinal sense, the outer frame being anchored at its two ends to the ends of the cable loop, the inner frame being provided with two elastic rollers against which the clamp trolley rests and thrusts, and being further provided with a tracer member operated by a lever mechanism actuated by the clamp trolley for lowering on the traction cable; said tracer being interlocked with a device for signalling and interrupting the flow of electric current to the installation, and acting only in the case in which sliding occurs between the clamp trolley and traction cable under the action of the braking torque. 